As is known, certain types of diseases, such as diabetes, call for injecting medications, such as insulin, several times a day, and the medication dosage to be injected may vary from one patient to another, and, for the same patient, during the day and from one day to another.
Over the past few years, therefore, electronically controlled injection devices have been devised and widely used to permit self-injection of medications in the required doses.
Patent Application US-A-2002/0133113 describes one such injection device substantially comprising a hand-held housing, which houses a cartridge containing the liquid medication for injection, and defines, on a contact surface for contacting the patient's skin, a through opening by which to fit a disposable needle to one end of the cartridge. The injection device also comprises an electromechanical actuator assembly, which is activated selectively to slide a plunger hermetically inside the cartridge body and deliver the liquid medication through the needle into the patient's skin.
Operation of the injection device is controlled by a programmable microprocessor, which receives signals from various switches and buttons—e.g. one or more medication dose selection buttons and an injection start button—and generates signals by which to control the actuator assembly according to a program stored in the microprocessor.
The injection device described therefore provides for selecting each medication dose for injection, and delivering the dose automatically.
Though functionally valid, the above type of injection device still leaves room for further improvement. More specifically, a need is felt for solutions designed to further reduce the amount of human intervention required, and to further safeguard users, with no medical experience, in preparing and self-injecting medications.